Question: $\dfrac{5}{2} - \dfrac{7}{4} = {?}$
Answer: $ = {\dfrac{5 \times 2}{2 \times 2}} - {\dfrac{7 \times 1}{4 \times 1}} $ $ = {\dfrac{10}{4}} - {\dfrac{7}{4}} $ $ = \dfrac{{10} - {7}}{4} $ $ = \dfrac{3}{4}$